Field of the Invention
The present invention relates to a printing system, a printing apparatus, a control method therefor, and a storage medium storing a program.
Description of the Related Art
In a printing market, there is a printing system that produces final products by applying various post-processes to printed sheets. One example of such post-processes is a cutting process, and a printing system is known that feeds a belt-like sheet such as a roll of paper, performs printing on the sheet, and cuts the sheet to a predetermined length. Also, as a printing system that feeds and performs printing on cut sheets and the like, a printing system is known that creates products by printing a plurality of images laid out on one sheet and then cutting the sheet with a post-process apparatus. For example, there is a function called double copy for printing a plurality of copies of A4-size sheets; in this double copy, two identical images are laid out and printed on an A3-size sheet, and then the A3-size sheet is cut to A4 size, that is to say, two copies of printed A4-size sheets are obtained. As the price of one A3-size sheet is lower than the price of two A4-size sheets in general, the use of the double copy function leads to cost reduction and improvement in productivity. Meanwhile, as a cutting apparatus that cuts sheets printed through double copy is generally arranged in the final stage of an entire printing system and completes discharge immediately after sheets are cut, it has a relatively small risk of sheet jam such as clogging of sheets.
Japanese Patent Laid-Open No. 2000-318245 describes a method of controlling a length to which a belt-like sheet is cut by a printing apparatus that prints an image on the sheet, cuts the sheet after the printing, and conveys the cut sheet to the outside of the apparatus. On the other hand, Japanese Patent Laid-Open No. 2007-83557 describes an image forming method for the case of double copy; in this method, upon issuance of an instruction for printing a plurality of copies, printing is performed through double copy, and if the number of the copies is an odd number, the last image is laid out and printed on the last sheet together with a blank image.
However, conventionally, no thought is given to a method of recovery from a sheet jam that occurs during the execution of a job in which a sheet printed using a double copy function is cut and conveyed. For example, after a sheet is cut in half, if one of the two cut sheets located upstream in a conveyance direction is jammed, the other sheet located downstream in the conveyance direction can be discharged normally because a conveyance path is not blocked by the jammed sheet located upstream. Then, recovery is performed in the following procedure: after the jammed sheet located upstream in the conveyance direction is removed, an A3-size sheet is fed again, and an image is printed on the fed sheet. In this case, as shown in FIG. 11, an image of the sheet located downstream in the conveyance direction, i.e., the sheet that has been discharged normally, is printed again on the fed sheet; in other words, a printed material is output in a redundant manner.
FIG. 11 is a diagram for describing a problem discussed in the present invention.
This is a case in which a cut sheet on which an image 8 has been printed, as well as subsequent sheets, is jammed. Prior to the cutting, a pair of images 7 and 8 was printed on an A3-size sheet 1101. After the sheet 1101 is cut, an A4-size sheet on which the image 7 has been printed is discharged normally, but a subsequent A4-size sheet on which the image 8 has been printed is jammed. In this case, one of the two images that were printed on the same sheet 1101 prior to the cutting is printed on the jammed sheet. Here, if recovery from the jam is performed through conventional control, a printing process for the A3-size sheet 1101 is restarted. This results in creation of two A4-size sheets on which the image 7 has been printed, that is to say, image redundancy.